sr20 cuttin out at higher rpm's??????????

[Miller White]

my best friend just bought a s13 with a s14 sr20 swap... it idles fine but at higher rpm's it just hits a wall and cuts out bad.. any one out there had any similar problems?

[IanS]

Search, go through the usual checks and make sure everything is good, if that doesnt fix the issue, try asking again.

[480sx]

Sounds like an ignition problem, gap your plugs down to .20 or less and see if that fix's it.

[Ilvemynissan]

It sounds like it could be the fuel pump....if it is he should probably get the Z32 300zx one. Works perfect in mine

[Ilvemynissan]

If he does replace it can you tell me how it works

[Miller White]

if it was one of those wouldnt it cut out all the time?

[480sx]

No, it wouldnt

Its sooo simple to gap your spark plugs, why dont you try that first and get back to us?

[IanS]

Everyone needs to just stop shouting out random fixes, its no way to solve problems.

To the OP, you need to search, there are many common issues that cause the problem you descriped. You need to go over the engine, checking off things, this way you can figure out what the problem is and fix it, instead of just stabbing at it in the dark.

Sounds like an ignition problem, gap your plugs down to .20 or less and see if that fix's it.

An ignition problem is a common source of high RPM misfires. But, you need to check your information. Im guessing that .20 was meant to be .020, am I correct? If so, .020 is far too tight of a gap for anything but a race engine, I would not recomend a gap smaller than .028 for stock or mildly tuned engines.

[Ilvemynissan]

Were not just shouting 'random fixes'.......thats no way to solve things dont ya know? That was what was happening to mine so I tried to help, I Apologize it wont happen again bud.

[480sx]

Yea i meant .02.

Regardless if its meant for race engines or not, gaping it down to whatever then testing it would tell you if its an ignition problem. O/C you want to run the biggest gap possible without blowout, but you start small then work your way up.

All we were trying to do is help this guy. Gaping the spark plugs is not a random fix. His problem sounds like a simple ignition problem and gaping the plugs would take two seconds of his time and could resolve his issue. Also, we gave him two possible suggestions about what his problem could be, while you gave him no information at all with the generic 'Search first' response.

In the time it took you to type out your posts you could have offered suggestions to the OP about what his problem could potentially be, and how to fix it. Saying go over the 'usual suspects' might mean absolutely nothing to this guy, which is probably the case because he's turned to asking Nico instead of going over that stuff first.

Not everyone is as car savvy as the rest of us(or search savvy), throw the guy a bone ffs.
Modified by 480sx at 11:31 AM 1/30/2008

[big monkey racing]

I have a similar on my ka24e motor. it idles alright but when I drive and hit about 4500-5000 it just stops and falls flat till about 2500-3000. any differences cause of the ka motor.

[IanS]

Yea i meant .02.

Regardless if its meant for race engines or not, gaping it down to whatever then testing it would tell you if its an ignition problem. O/C you want to run the biggest gap possible without blowout, but you start small then work your way up.

All we were trying to do is help this guy. Gaping the spark plugs is not a random fix. His problem sounds like a simple ignition problem and gaping the plugs would take two seconds of his time and could resolve his issue. Also, we gave him two possible suggestions about what his problem could be, while you gave him no information at all with the generic 'Search first' response.

In the time it took you to type out your posts you could have offered suggestions to the OP about what his problem could potentially be, and how to fix it. Saying go over the 'usual suspects' might mean absolutely nothing to this guy, which is probably the case because he's turned to asking Nico instead of going over that stuff first.

Not everyone is as car savvy as the rest of us(or search savvy), throw the guy a bone ffs.

Modified by 480sx at 11:31 AM 1/30/2008

I see there was a little misunderstanding, when you said .02 I assumed you were telling him this is the gap he should run normaly, this is incorrect. For testing purposes it is fine, but if he is getting blowout even at .03 then the problem lies deeper. I did not mean to come off like an a$$, but you guys are trying to trouble shoot backwards.

when you have a problem, you dont just start throwing fixes at it left and right, you first must figure out the cause. To truly diagnose the issue, the first thing to do is, check over the engine, make sure nothing is loose, broken, or leaking. Then you can move on, the next step should be detirmining what the cause is, a quick look at the spark plugs should tell you what in general is causing the missfire, whether it be a lean condition, rich condition, or an ignition failure.

This should lead you to a conclusion, is it fuel related, or is it ignition related. If it is fuel related, you will need a fuel pressure gauge and an ohm meter. If it is spark related, you will need to check plug gaps, and check the coil packs and ignitor.

In my years running the SR20 I have had numerous problems with missfires above 4000 RPM. All of them caused by issues with the ignition system. I have seen copper plugs that wore down and increased the gap, causing blowoutI have had coil packs fail for no apparent reasonI have had coil packs crack in inconspicuous places, so they test ok, but allow spark to escape into the headI have had coil pack bolts break off allowing the pack to jump up and allow spark to escape under the bootand I have had coil pack boots crack and allow spark to carbon track through them.

Many people have these same issues with the SR. If you are not car savvy enough to do your own basic troubleshooting, then a forum is no help, the car should go to a capable mechanic. The generic search response is often the best, because if the person is not smart enough to search, why are they working on the car in the first place, if you just give a guy the answer, he may get his car fixed this time, but if you tell him to search maybe he will learn a little something along the way, there by becoming a more helpful part of society.

[Miller White]

people need to ****ing chill....... today we tested it after "fixin" a few wires, today it cut out at around 3000 rpm's... wat kinda maf is the best to run on a s14 sr20 in a s13

[Vegascorbin]

In need of education. I have never heard the term "Blowout" in referance to spark plugs before. I understand what you mean (the air/fuel mixture moving through the cylinder blows out the spark before it can ignite the mixture.) I also understand that this can be caused by too large a plug gap or a weak spark caused by bad wires/coil etc.

What I don't understand is how to tell when you are suffering blowout as oposed to other problems.

[UncleBen]

miller, cursing at people trying to help you is definately the way you should handle things let me tell ya....

Did you not read anything at all that was said above? Use the damn search button, motor's aren't really that difficult. Obviously you're 'fixin' of wires made the problem worse, so go back and undo what you just did and start listening to what sideways-smiles has to say.

[IanS]

In need of education. I have never heard the term "Blowout" in referance to spark plugs before. I understand what you mean (the air/fuel mixture moving through the cylinder blows out the spark before it can ignite the mixture.) I also understand that this can be caused by too large a plug gap or a weak spark caused by bad wires/coil etc.

What I don't understand is how to tell when you are suffering blowout as oposed to other problems.

Spark blowout is just one cause of a misfire. There are three main types of misfires. Pre detination, late detonation, and failed detonation. Late detonation is a whole other bag of issues, so we will concentrate on the other two.

Pre detonation, also known as knock, or auto ignition. Knock happens when the air fuel mixture is ignited by something other than spark, this ignition happens before the piston reaches TDC. The main causes of predet are, overheating, spark plug heat range too high, lean AFR, or mis adjusted timing. Knock is very hard on engines, it can cause bent rods, cracked pistons, holly pistons, rod bearing failure, and bent or burned ring lands. Knock is often heard as an audible knocking noise coming from the engine, accompanied by a sharp loss of power.

Failed detonation. When spark fails to ignite the air fuel mixture. This failed ignition is most often caused by issues with the ignition system itself, though an extreme rich condition can also cause failed or late detonation, it is usually accompanied by black exhaust smoke. What makes failed detonation so difficult to diagnose is the multitude of causes. The ignition system on the SR20DET is rather complex, there are quite a few things that can be the problem, and they will all have similar symptoms. Something like a failed coil pack will cause a dead cylinder which is easy, where as a partially failed coil pack, or a coil pack with a crack in it, or its boot will have the same symptoms as an over gapped spark plug or a loose spark plug to coil connection. All those issues cause the symptoms we are discussing, a semi random misfire, only noticed at mid to high RPM.

The reason the misfire only occurs at mid to high rpms is due to a few factors. When an over gapped spark plug is the issue, the increasing airflow or boost at higher revs blows the spark out before it can ignite an adequate flame front. If a failing coil is the issue, the higher rpms begin to put too much load on the coil itself, causing it to fall behind, either not firing enough, or not producing enough voltage for proper spark. If the coil pack or coil pack boot is cracked, as rpms increase, so does voltage, that voltage will always choose the path of least resistance. When the voltage reaches a certain point it may choose to jump though the cracks in the coil pack or its boot strait into the head itself.

As apposed to pre detonation, where a sharp loss of power is felt, a random misfire caused by failed detonation will feel more like a stutter, varying in strength, determined by the source of the problem. Another issue is the intermittence of the problem, some people will only notice the stutter when humidity is high, or when it is raining, others only when ambient air temp is high.

I would delve further into the subject but my A.D.D. is acting up, and I cant seem to translate thoughts into words properly, which means this post is probubly full of spelling and grammer errors. I hope this information was helpful.

[Vegascorbin]

Thanks! that is the type of explanation I was looking for. My engine is a KA24E not an SR20 but the theory is the same. Based on what you said and other tests I think my problem is the engine is getting fuel starved not spark starved.

Thanks

[Ilvemynissan]

Did you ever figure out the problem or was this thread worthless??

[Vegascorbin]

I was going to wait until I had Pictures but as you asked, Yes we did find part of the problem.

The major problem we found on Saturday was the #3 rod cap was sitting on top of the cross member. And the rod was right behind it.

We blew a BIG hole in the side of the block (driver side) during the 1st heat on Saturday When I say big I mean about 3"x5" plus at least one more hole in the oil pan. Time to find out if our extra motor is any good.

That's what happens when you go racing. When we actualy open the motor we will let you guys know if we find anything else that may help others.

[0wn3r]

wat kinda maf is the best to run on a s14 sr20 in a s13

an S14 SR20DET MAF. if it's a zenki motor, you probably need a zenki MAF, but to be honest i don't have a zenki motor so never tried a kouki MAF. if it's a kouki, you need a kouki MAF. talking stock anyways.

if you're using the wrong one, this could be related to the issue.
Modified by 0wn3r at 9:25 AM 2/11/2008

[Miller White]

I put new plugs in and gapped them to .028. The plugs i pulled were wet with gas and black, but this didn't fix the problem. I'm waiting on a s14 maf sensor. It had a s13 one on it and now it has a sohc ka one on it. Any more suggestions would greatly be appreciated. thanks guys. oh and 1 more thing, can you run a sohc ka maf without a air fuel controller?

[Miller White]

Oh yeah and is it possible that it could be the fuel pressure regulator? it has a pretty old 1 on it

[IanS]

The only MAFs that will work with the SR, without retuning, are the SOHC KA24E, and the JDM SR20DET.

[Miller White]

What bout the fpr? it was running really rich, it was smoking a little and had a little backfire to it

[IanS]

What is your fuel pressure?

[0wn3r]

The only MAFs that will work with the SR, without retuning, are the SOHC KA24E, and the JDM SR20DET.

I'm hoping he knew that I meant an SR20DET MAF... if you have an S14 motor, you need to know if it's zenki or kouki. if you try to run a zenki MAF on a kouki motor, it will run like crap too.

[Miller White]

I don't have a gauge on it. I found a leak in a vacuum line coming off my bov. fixed it, but it didn't help. I noticed when it stalls the bov goes off and sometimes it throws a cloud of black smoke out the exhaust. I have a HKS ssqv, are they adjustable? i looked at it and couldn't find a way to adjust it. I also pulled the new plugs and they were black, not as bad as the other plugs i pulled tho. I'm sorry about all the questions, this is my first turboed car and i really appreciate all the help ya'll have been thanks.

[Miller White]

I also checked the light on the ecu in diagnostic mode and it blinked once when i turned the key to the run position and once in run and in diagnostic mode it didn't flash or come on at all. Could this be a problem?

[IanS]

sounds like you need to recirculate your BOV.

[arley23]

check your timing